Doh. Well spotted.
Looking back in SS in my original version I had dataPtr = ((u1*)bmPtr +
sizeof(BitmapType)); but I moved the cast when I cut and pasted :(
cheers again,
Idries
> -----Original Message-----
> From: Ben Combee [mailto:[EMAIL PROTECTED]]
> Sent: 30 May 2002 13:54
> To: Palm Developer Forum
> Subject: RE: Drawing performance (was Access screen with Palm OS 4.0)
>
>
> In article <87618@palm-dev-forum>, [EMAIL PROTECTED] says...
> > One more problem that I am having, is accessing bitmap data
> on pre OS 3.5.
> > On 3.5 I can use BmpGetBits (and I was never doing that
> every frame :) and
> > on pre 3.5 I am using just incrementing my BitmapPtr by
> sizeof(BitmapType)
> > because the documentation says that the bitmap data is
> stored just after the
> > BitmapType struct. My bitmaps do not have colour tables,
> but getting a
> > pointer via this method just gives me garbage, anyone know
> where I'm going
> > wrong?
> >
> > u1* dataPtr;
> > BitmapPtr bmPtr;
> >
> > dataPtr = (u1*)(bmPtr + sizeof(BitmapType));
>
> Write
>
> dataPtr = (u1*)(bmPtr + 1);
>
> or
>
> dataPtr = (u1*)((char *)bmPtr + sizeof(BitmapType));
>
> Remember that adding 1 to a pointer increments it by the size
> of what it
> points to. You were effectively incrementing your pointer by sizeof
> (BitmapType) squared.
>
> --
> Ben Combee <[EMAIL PROTECTED]>
> CodeWarrior for Palm OS technical lead
> Get help at http://palmoswerks.com/
>
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